As the new market has been created and the development of technology has progressed in the field of displays, various types of new display products such as LCD, LED, PDP, AMOLED, and the like have been developed.
In particular, in these display products, the mounting of a touch screen together with 3D has already been essentially employed in the display region due to the implementation of a user-centered interface and the implementation of entertainment functions.
The use of the touch screen panel has started from PDAs and now widely used in automated teller machines (ATMs), self-ticketing machines, mobile phones, navigators, weather forecast for televisions, karaoke, game devices for video arcades, and the like.
Examples of touch panels which are a transparent input device include optical-type, capacitive-type, ultrasonic-type, resistive-type, electromagnetic induction-type touch panels, and the like according to the driving principle thereof, and the touch panels are classified per use and characteristics according to the principle thereof, and used.
The resistive-type touch panels are usually used in mobile devices such as mobile phones, game devices, PDA, navigators, and the like, because characteristics such as lightweight, thin type, power saving, low costs, and the like of the resistive-type touch panels are utilized.
Moreover, optical-type, capacitive-type, or ultrasonic-type touch panels are used in devices such as ticketing machines, ATMs, game devices for video arcades, and the like, which many and unspecified persons use.
Although resistive-type touch panels have an overwhelming market share of 90% or more in LCD-mounted touch panels, a capacitive-type touch panel is employed in iPhones by Apple, Inc.
For resistive-types, capacitive-type and ultrasonic-type touch panels, a certain amount of conductor and inductor materials are added on the surface thereof. In particular, semiconductor films, such as indium tin oxide (ITO) film, and the like, are used in resistive-type and capacitive-type touch panels, and thus the reflection ratio thereof is high.
Laminates are not added on the surface of an optical-type touch panel and optically advantageous.
In general, resistive-type touch panels have a pressure sensor between electrodes, which is driven according to the principle of sensing micro-pressure, and are advantageous in that the panels have low costs compared to capacitive-type touch panels and are excellent in document preparation and handwriting recognition. However, the resistive-type touch panels are disadvantageous in that the external appearance thereof is easily damaged and multi-touch tasks are difficult for the panels to perform.
On the contrary, capacitive-type touch panels are driven according to the principle of recognizing micro-electric current of a human body, and are advantageous in that the panels are excellent in response speed and scratch resistance, capable of performing multi-touch tasks, and high in transmittance due to a structure of responding to electric current. However, the capacitive type panels are disadvantageous in that the panels have high manufacturing costs and are poor in document preparation and handwriting recognition.
In capacitive-type touch panels, PET film or glass may be used as a protective layer, and in particular, tempered glass is used in glass-type capacitive-type touch panels.
Depending on the kinds and manufacturers of display products using a capacitive-type touch panel, there are differences in structure and manufacturing process thereof. However, usually on tempered glass, electrode patterns using ITO are formed, or Bezel patterns for hiding the circuit wiring around an input unit are formed on tempered glass.
Bezel patterns to be formed on tempered glass of a touch panel may be formed by using a photolithography method or a screen printing method in the related art.
However, when the photolithography method is used, a uniform and precise Bezel pattern may be obtained, but the method includes processes of coating-exposure-development-sintering, and thus requires high costs.
In particular, after a pattern is formed on a large-size tempered glass substrate, it is impossible to cut the tempered glass substrate into a desired size and shape and use it. Thus, manufacturing is carried out by using a sheet of each glass substrate which has been subjected to tempering treatment after the glass is already cut into a specific standard and size, thereby causing a very inefficient manufacturing of the above.
Further, when screen printing is used, Bezel patterns are advantageous in that the patterns may be readily formed at a very fast speed, but disadvantageous in that the patterns have a thickness of 5 μm or more and are poor in thickness uniformity.